Sure and Turf is a known morale booster and we did get it once a week during the war. We had stir fry night as well. We also could request meat for BBQs and do it ourselves ( at least WE could in SOF).
It’s not true that it’s a sign of pending deployment orders each and every time. The Mess Officer or Commander can request the troops be served any type of meal for certain events like the Army/other Birthday, Memorial Day, thanksgiving or Christmas.
I will say if you show up on and random day and see this on the serving line you might be fucked (reference the spaghetti meal scene in Band of Brothers).